Deboth, alternatively referred to as Dark Species Deboth, is the main antagonist in Zyuden Sentai Kyoryuger. Known as the "Planetary Illness", he is the source of the Deboth Army in Zyuden Sentai Kyoryuger. Near the end of the series, Deboth evolves into a humanoid form, now calling himself Transcendenterfly God Deboth.
Created by an unknown figure with the ability to adapt the characteristics of those it deems the dominant life form, Deboth travels the cosmos to use these races to evolve before reducing the planet to a dead world with his melody. To aid him, Deboth created Chaos and Torin as his heralds, with the latter sent to Earth during the Mesozoic Era. However, Torin betrayed Deboth and assembled the Zyudenryu, dinosaurs who became fighting machines, to face him when he comes to Earth personally. During the fight, once gaining the ferocity of the dinosaurs that D collected with Topaspino's forced aid, Deboth evolves into his prehistoric and creates Gadoma to aid him before both are mortally wounded by Bragigas's Gigant Cannon. With his heart damaged, with some of his cells scattered across the planet, Deboth' body entered a dormant, plant-like state before Torin seals it away in the Antarctic seabed, where there it came to be known as the Frozen Castle.
Deboth's thawing and the collecting of human emotions becomes the objective of the Deboth Army, an organization who membership are beings spawned from Deboth's cells and under Chaos's command. Eventually, Chaos uses a dam filled with Restoration Water to revive Deboth yet he lacked enough emotions to fully thaw out his heart and is rendered a mindless monster that overwhelms the Kyoryugers before being seemingly destroyed by Bakurestsu Kyoryuzin.
But in reality, Deboth transfered his heart into Chaos while his comatose body was only damaged and eventually healed. By the start of next year, with the aid of Endolf, Aisurondo and Kirubolero, Chaos gains the emotions needed for Deboth to become fully aware again. Borrowing Chaos's body, Deboth returns to the Frozen Castle and fuses his heart back into his original body before condensing his being into a fragment that breaks off as it becomes his new human sized body. In his new form with knowledge of "melody" within the hearts of humans, Deboth's melody of darkness is augmented with an insane amount of speed and power while able to cancel the Kyoryugers' transformation. From there, rising the Frozen Castle above the planet, Deboth begins the countdown to the genocide of Earth before facing the Kyoryugers' Daigo Kiryu with the Maximum and Victory Zyudenchi that can destroy him. Though he had the upper hand against Daigo, Deboth finds his team are disrupting his melody before he is destroyed by Kyoryu Red Carnival while his Frozen Castle body is obliterated by the Zyudenryu.
- Deboth's sense of superiority and agenda to evolve into a perfect life form are similar to Cell and Doras.